Chapter 14: Nervous System – Spinal Cord and Spinal Nerves

These flashcards cover key concepts related to the spinal cord, spinal nerves, neural pathways, and reflexes as presented in the lecture notes.

Spinal Cord

Extends from the medulla to the lumbar region, ending at the L1 vertebra.

Conus Medullaris

The tapered end of the spinal cord located at the L1 vertebra.

Cauda Equina

A collection of spinal nerves and nerve roots located below the conus medullaris.

Filum Terminale

A fibrous extension from the conus medullaris that anchors the spinal cord to the coccyx.

Gray Matter

Made of neuron cell bodies, dendrites, unmyelinated axons, and glial cells.

Anterior Horns

Houses cell bodies of somatic motor neurons.

Posterior Horns

Contains axons of sensory neurons and cell bodies of interneurons.

Nuclei

Groups of cell bodies in the spinal cord; includes sensory and motor nuclei.

White Matter

Contains myelinated axons that carry information to and from the brain.

Sensory Pathways

Pathways that ascend toward the brain; involve primary, secondary, and tertiary neurons.

Motor Pathways

Pathways that descend from the brain to control effectors like skeletal muscles.

Spinal Nerves

31 pairs of nerves formed by posterior and anterior roots merging.

Dermatome

A segment of skin supplied by a single spinal nerve.

Nerve Plexus

Network of interweaving anterior rami of spinal nerves; includes cervical, brachial, lumbar, and sacral plexuses.

Reflex Arc

The neural pathway that mediates an involuntary reflex response.

Monosynaptic Reflex

A reflex involving a single synapse between a sensory and a motor neuron.

Polysynaptic Reflex

A reflex that involves one or more interneurons between sensory and motor neurons.

Stretch Reflex

A reflexive contraction of a muscle in response to its stretching.

Withdrawal Reflex

A reflex that causes the withdrawal of a limb from a painful stimulus.